NIST researchers have conducted a study measuring the damaging effects of radiation on qubits, the fundamental units of quantum information. Qubits are highly sensitive to changes in temperature and radiation, which can cause them to lose their quantum state or become entangled. The study used silicon chips similar to those used in superconducting qubit circuits and cooled them to ultra-low temperatures. Researchers employed a new type of superconducting energy-sensitive sensor called a thermal kinetic inductance detector (TKID) to measure the rate and energy of gamma rays and cosmic rays striking the silicon.
The study confirmed the accuracy of models predicting the effects of gamma rays and cosmic rays, allowing the team to assess the damaging effects of terrestrial gamma rays and cosmic rays over a wide range of energies. They found that cosmic ray particles, specifically protons and neutrons, caused the most energetic disruptions in the silicon chips. The study revealed that radiation pummeled a 1,500-micrometer thick chip more frequently and dumped two to three times more energy than in a 500-micrometer-thick chip. Shrinking the thickness or size of the silicon or thermally insulating the thin-film qubit circuit from sections of the underlying silicon chip could help reduce disturbances in the qubit circuits.
The study, published online on Nov. 12 in PRX Quantum, is one of the first to use TKIDs to measure the energy of charged particles and could help improve the design of quantum computers to make them more resistant to radiation damage.
Source: https://www.nist.gov/news-events/news/2024/11/nist-study-probes-damaging-effects-radiation-qubits
Keywords: Quantum states, Radiation effects, Silicon chips, Superconducting qubits, Entanglement
